Background and objectives: This study was aimed to investigate the effects of miR-650 on the proliferation, migration, invasion and apoptosis of rheumatoid arthritis synovial fibroblasts (RASFs). Methods: Synovial tissue samples were collected from 16 rheumatoid arthritis (RA) patients and 13 patients with joint trauma undergoing joint replacement surgery. The RASFs were isolated and cultured. MiR-650 and AKT2 expressions in both synovial tissues and cells were detected using the quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry (IHC). Dual luciferase reporter gene assay was employed to evaluate the effect of miR-650 on the luciferase activity of AKT2. Then RASFs were transfected with miR-650 mimics, miR-650 inhibitors and pLenti6/V5-AKT2 respectively. And changes in cellular proliferation, migration, invasion and apoptosis were detected through MTT assay, wound healing assay, Transwell invasion assay and flow cytometry analysis, respectively. Results: MiR-650 was significantly down-regulated in RASFs than normal cells, whereas AKT2 was up-regulated in RASFs. Dual luciferase reporter gene assay showed that miR-650 could specifically bind to the 3/UTR of AKT2 and significantly repress the luciferase activity. MiR-650 significantly decreased the expression of AKT2. Down-regulation of miR-650 or up-regulation of AKT2 could increase proliferation, migration, invasion of RASFs, and decrease RASFs apoptosis. The conversed results were observed, when miR-650 was up-regulated in RASFs. Conclusions: MiR-650 could inhibit the proliferation, migration and invasion of RASFs through targeted regulation of AKT2 expression. (C) 2017 Elsevier Masson SAS. All rights reserved.